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Executive Summary Remote sensing and computer technologies have developed to the point where great new advances in real-time weather observing and forecasting are possible. An opportunity exists to make ah phases of the manned and unmanned space programs more efficient, less threatened by delay, and free of weather-related hazards that could lead to damage or loss of spacecraft or even human lives. It is vital to make improvements within the meteorological support and launch decision Infrastructure of NASA that may avert a repetition of tragedies such as the AtIas-Centaur 67 destruction on March 26, 1987, and the Space Shuttle Challenger explosion on January 28, 1986. This report recommends mechanisms by which NASA can put into operation state-of-th~science meteorological technology and ad- vanced weather forecasting techniques to enhance the efficiency, re- liability, and safety of space operations. The spirit motivating these recommendations is the panel's belief that NASA should strive to exploit the benefits of the cutting edge of new meteorological tech- nology, just as it exploits the potential of the numerous other tech- nologies that support space flight. In striving to reach this goal, NASA can pave the way for many other applications of these ad- vanced meteorological capabilities. 1
2 Since the inception of the shuttle program, the needs for mete- orological support have become clearer and the quality of the me- teorological support available has improved. However, it became obvious to all members of the pane! early In this stucly that NASA has not had a coordinated meteorological support program. Owing to this lack of coordination, space program needs and meteorological expertise have not yet been adequately brought together. The need for a coordinated and improved weather support pro- gram has already been expressed by others within NASA. In October 1986, the NASA Space Shuttle Weather Forecasting Advisory Pane! (John Theon, chairman) issued its findings and recommendations to the NASA associate administrator for space flight. Their first and foremost recommendation was that "Shuttle weather services must be organized in such a way to bring them up to the very best state-of-the-science and technology and under an optimal manage- ment situation. Toward this end, they recommended that "NASA should establish a Weather Support Office at the top level of Shuttle operations to plan, organize, focus, and direct the activities related to Space Shuttle weather support." The Pane} on Meteorological Support for Space Operations endorses this recommendation. (All recornrnendations from the Theon report are reproduced in Appendix C of this report.) In the report that follows, the pane! amplifies some of these earlier findings and adds additional recommendations. The task of reorganization wait not be simple. Meteorological support for space operations is at present fragmented. The U.S. Air Force Air Weather Service provides observing and forecastin personnel at Kennedy Space Center (KSC), Vandenberg AFB, and Edwards AFB. NOAA provides support to Johnson Space Center (]SC). A private meteorological firm provides forecasting service for the Wallops Island, Virginia, Flight Facility. The Marshall Space Flight Center (MSFC) provides some technical guidance to both KSC and JSC, and other groups are also involved, including con- tractors. The various participants report to different organizations within NASA. Following the Theon report and the formation of this panel, a Weather Support Office (WSO) was created within the Office of Space Flight (OSF), and on December 6, 1987, a director was appointed. To bring about substantial improvements in weather support, it is now imperative that NASA give clear and unambigu- ous authority to the WSO, and grant it sufficient budget authority to
3 ensure an integrated and coordinated meteorological support pro- gram for all ground, launch, landing, and recovery activities. Weather support for manned and unmanned space Light should be a single co- hesive program coordinated through the Weather Support Office. This pane! urges that all possible support be directed to this vital aspect of space operations. There are many good scientists and technicians involved In meteorological research and support activities within NASA, but they are not sufficiently focused on the operational problems of space flight. Each of NASA's research centers should be strongly encouraged to commit some of its resources in the effort to upgrade meteorological support for the space program. Although Air Weather Service and National Weather Service forecasters have been supporting space operations with skill and ded- ication, the technology and techniques they have employed up to this tune are not adequate to meet unique and stringent future require- ments. Up to this point in the space program, launches have been relatively infrequent and delays have been accommodated. Thus it has, in principle, been possible to wait until ordinary meteorologi- cal observations have indicated an ideal launch window. However, there remains the concern that conventional techniques might fad! to detect certain hazards. As launches are scheduled more frequently, delays will become less tolerable. There will be a need to identify a greater number of low-risk launch windows. This task requires im- proved observations and predictions of many special meteorological variables and phenomena of unique significance to space launches- e.g., triggered lightning, precipitation size and type, wind shear, and turbulence with a degree of sensitivity, timeliness, and accuracy unique to the space program. The pane} offers the following recommendations so that as the space program moves into a revitalized era, space program personnel may use meteorological information with confidence during all phases of space operations. Recommendations are spelled out in greater detail in subsequent chapters, where expanded justification rationale · - a so given. RECOMMENDATIONS The pane! identified five principal categories of deficiencies in the program of weather support for space operations: 1. Quantification of weather hazards.
4 arcs. arcs. 2. Observing systems capable of detecting specific weather haz 3. Analysis and forecasting schemes for specific weather haz 4. Coordination of applications research and operational pro- grams. 5. Organizational structure to promote continued improvement of weather support as needs change and capabilities improve. A chapter in the report has been devoted to each of these prin- cipal deficiencies (although not exactly in the sequence presented here). The key recommendations addressing each of these problems are presented below. Additional observations and conclusions are highlighted within the chapters of the text. Recommendation 1: With expectation of more frequent launches and an associated decrease in the margin of weather safety, it is imperative that NASA quantify more rigorously the relationships between magnitudes of weather variables and the hazard they pose to space vehicles. Flight ~es and launch commit criteria shown be based on these relationships. Many of the meteorological variables critically affecting space operations have not been adequately quantified to the point where weather support can be focused on specific threshold values. At the same time, Space Shuttle program managers have not defined precisely what weather information is needed. Thus the weather support system has not been able to concentrate sufficiently on the special problems of the Space Shuttle. Some critical parameters are currently not measured such as drop sizes in clouds and rain, which are hazardous because of the possibility of protective tile damage- and there is no program to initiate these types of measurements. At the time when the Atias-Centaur spacecraft was destroyed, NASA and the Air Weather Service were operating the largest network of electric field mills in the world, but measurements of electric fields had not yet been incorporated into the weather commit criteria as a guard against triggered lightning. Wind shear and turbulence criteria are also not quantitatively defined. Recommendation 2: New and improved ~ne~umentation nmet be used to detect weather condition and phenomena that are hazardous to space operations.
s Many of the weather elements most critical to space operations are not being measured directly. Their existence is being inferred through relationships with other, directly observable, parameters. For example, lightning strikes in clouds, and the electric fields that provide a potential for triggered lightning in clouds, are inferred from surface-based electric field readings. Launch-time wind and wind shear hazards are estimated by using soundings prior to launch in conjunction with climatological statistics of expected short-term wmd variance. These types of indirect hazard assessments are ac- ceptable when no other options are available, but when more direct measurement systems are available they should be used. Displays from additional existing lightning detection networks should be made available in the KSC weather forecast office, and a new system should be developed to detect in-cloud lightning. Tnstru- mented aircraft should be used to measure electric fields aloft that could lead to triggered lightning and to measure the types and sizes of precipitation that could damage the Space Shuttle. Multiparame- ter radar and ground-based dis~rometers should be used to examine the temporal and spatial variability of precipitation type and size. A network of wind profilers should be used to detect rapidly changing patterns of wind and wind shears or to ensure their nonexistence. Several Doppler radars should be deployed to detect probable areas of wind shear and turbulence and to identify low-level wind conver- gence zones ~ which thunderstorms are likely to form. Alternative landing sites overseas have, until now, been equipped only with rudimentary instrumentation and have, in some cases, relied on local observers. These sites should be surveyed to ensure the availability of adequate weather observations for safe recovery. Recommendation 3: A neither of emerging te~hn;ques for weather analyst and forecasting and decision making must be actively purmed. The Introduction of new instrumentation should immediately improve detection capabilities, but it will not necessarily ensure im- provements in weather forecasts. Present weather forecasting tech- niques have been developed for use with the types of data previously available and will need to be modified to incorporate new data bases. Improvements in knowledge of the quantitative relationships between weather elements and space flight risk will necessitate a fine-tuning of weather forecasts to accurately predict specific values of particular weather variables.
6 Techniques to be developed include a local weather analysis system, an interactive computer-a~ded dec~ion-mak~ng system, and nested grid numerical weather prediction models. Recommendation 4: To bring about substantial Improve meets in weather support, it is imperative that NASA Blue clear and unambigno~ authority to the Weather Support Offlce and give it sufficient budgetary authority to ensure an integrated and coordinated meteorological support program for an phases of the manned and unmanned space programs. It has been made clear by the Theon report, and in all of the presentations heard by this panel, that the organizational structure of NASA has inhibited an integrated and coordinated weather support progrmn that would focus NASA's considerable technological and human resources and expertise on NASA's operational space flight problems. The primary mission of the WSO should be to mobilize and coordinate as many of these resources as possible toward one objective: to develop and implement new technologies for observing, analyzing, and forecasting the weather elements most critical to the space program. In the context of this report, WSO should serve as the administrative office charged with ensuring the execution of the other recommendations. Recommendation 5: An Applied Research and Forecasting Facility (ARFF) should be established at Kennedy Space Center to promote the development and application of new measurement technology and new weather analysis and fore- castmg te~hn;qlles to improve weather support for space op- erations, to provide forecaster education and try nag to coordinate field programs involving the meteorological com- mlmity, and to conduct an active visiting scientist program. The paramount function of the Air Weather Service detachment at the Cape Canaveral Forecast Facility, which services KSC and the NOAA group at JSC, is to provide operational weather support on a daily basis for the many launches and ground activities in progress. Neither group has a mission to conduct research, and they are not adequately staked to coordinate new programs to develop and install advanced instrumentation and new techniques for weather analysis and forecasting at KSC. However, the unique weather sensitivities of the space program dictate that new observing systems are required
7 in order to improve the quality of weather support. A great deal of effort is required to develop procedures for using these systems to improve operational weather analysm and forecasting and to train operational weather forecasters to use these procedures. Thus an ARFF is needed to help the WSO in the minion of developing new observing, analysis, and forecasting technologies. This assistance should include the special tasks of determining how best to use the technologies in the KSC environment and of transferring the technology to the operational forecast offices. These tasks should employ an experimental weather forecasting facility within ARFF where new techniques can be tested and operational forecasters can be stationed for training. An advisory committee should be formed to assess for WSO the ongoing efforts to unprove weather support and to suggest additional or alternative approaches. CONCLUDING REMA}~53 The National Aeronautics and Space Adm~n~tration has been poorly organized to provide weather support, and the result ~ a sys- tem that ~ less than state-of-the-science. Unless radical changes are made now in the way services and applied research are coordinated, weather will loom larger as a threat to a rejuvenated and accelerated space flight program. To make available greater numbers of safe launch and recovery windows and to provide a more complete recog- nition of hazards that are at present poorly observed and predicted, a larger, more comprehensive, and better integrated program will be required. This program will require rapid technology and technique development, testing, and transfer to operational status. The pane! believes that, in order to maximize the safety of launches of manned and unmanned vehicles and landings of the Space Shuttle, the space program most critically needs current weather in- formation and forecasts valid for 2 hours or less. The quality of the latter very-short-term forecasts (or "nowcasts") is often, in reality, limited by the quality of the observations. Accordingly, the pane! places the highest priorities on the improvement of existing observ- ing systems and on the deployment of new measurement systems. Farther, these actions can yield almost immediate improvements in weather support. Observations of lightning, electric fields aloft (in order to identify nonelectrified clouds that are safe to penetrate), and rapid wind variations are most urgently needed. The pane] advocates
8 implementation of the following actions as rapidly ~ possible: in- strumenting an aircraft to measure electric fields aloft, wind velocity, and turbulence along the launch/landing paths; installing a single wind profiler to detect sudden wind changes; and installing displays of additional lightning detection networks in the weather office to monitor thunderstorm systems approaching the KSC area. The de- velopment of forecasting techniques can follow, and benefit from, the new instrumentation. Because of its high visibility, the space program is a critical focal point from which the public, the national and international scientific communities, and the nation's decision makers derive their perceptions of the scientific, engineering, and technological expertise in the United States. It is incumbent on all scientists and engineers to be sure that the best technology and expertise are utilized to ensure the success of the program.